Not too long ago we wrote about the best five-cylinder engines ever made, running through cars like the Audi RS3 and Ford Focus RS, the motors of which we absolutely adore. It would be rude to stop at the five-pots, though, so now it’s time to run through the best four-cylinder engines ever made. The four might not get as much love as a five, six, eight or 12, but there are still some truly awesome engines to take a closer look at.
As is the norm, we have to start at the beginning, which isn’t controversy free. Mercedes-Benz claims that the Daimler Phoenix was the world’s first road vehicle to be fitted with a four-cylinder engine in 1898. However, over in the USA, a man named Herbert H. Buffum had begun work on a four-cylinder car in 1894, completing the Buffum Four Cylinder Stanhope in 1895 in Massachusetts. The four-cylinder was of Buffman’s own creation, and was by today’s standards relatively basic (it used a ‘make-and-break’ spark system, for example), but it was a four-cylinder none the less, and all he needed was a chassis. So Buffum turned to carriage maker George Pierce who created a tubuluar chassis into which the engine sat transversely (the starter handle was therefore at the side of the vehicle), the power from which went via a two-speed planetary transmission and chain to the rear wheels. On top of that went a Pierce ‘Stanhope’ body, and the front wheels were steering with a tiller. The car you see here, the original vehicle that Buffum built but often hid away at home so no one could steal his ideas, was sold by Bonhams in 2012 for £113,500.
The BMC A Series was never the most powerful four-cylinder engine in the world, nor was it particularly revolutionary, but it remains one of the most popular engines of all time. Launched in 1951 under the bonnet of the Austin A30, every single version of the engine made had a cast-iron block and cylinder head, and goodness, were there plenty of versions… The smallest capacity BMC A Series engine was 803cc, the largest 1,275cc. The least powerful had 15PS (11kW), a diesel no less, while the most powerful was the 1,275cc unit with a small turbocharger bolted on. You’d think a good run for an engine would be 20 years, perhaps? Well the A Series lasted nearly 50, production ending with the last of the ‘original’ Minis in April 2000. Because of the engine’s popularity, if you own an A Series powered machine today and need a spare part you almost certainly won’t have trouble finding one, used or new, as plenty of businesses now manufacturer spares to cater for the huge market.
Another engine that lasted for decades is the Alfa Romeo Twin Cam. Introduced in 1954 in the Alfa Romeo Giulietta, the work of Italian designers Orazio Satta Puliga and Giuseppe Busso (yes, that Busso) it was an advanced little unit, certainly more impressive than its predecessor, the 1900. Instead of an iron block it used aluminium alloy, an unprecedented idea in 1954, with cast iron wet cylinder liners, and it featured an aluminium alloy head, a steel crankshaft, double overhead camshafts and more. It was a modest creation at first, measuring 1,290cc in the Giulietta, and there were two other versions with even less capacity. But for the most part the Twin Cam went up in capacity and performance, powering the Spider, Giulia, Junior, Alfetta, 75, 164, 155, 164 and more, with tweaks along the way and countless updates (including Twin Spark and turbocharging), the result of which was a production run that lasted until 1994. The engine was also breathed on by Autodelta, the performance division of Alfa Romeo, winding up the power, torque and rev limit for various racing adventures.
What is the smallest four-cylinder engine ever fitted to a road car? The AK250E in the Honda T360, measuring just 356cc. We’ve written about our love for Kei cars on multiple occasions – in fact we did a list of the 10 best kei cars of all time not too long ago. We love the looks and the preposterousness of these teeny machines, but we also love the creativity that comes with such a strict set of boundaries to work with when it comes to car size, emissions, engine capacity and more. The T360 truck – yes, it is a truck – is another incredible Kei car. The tiny engine sat under the bench front seat, making it mid-engined and therefore basically a Ferrari, with power going to the rear wheels via a four-speed manual ‘box. Speaking of power, that pipette-sized motor made 30PS (22kW) at 8,500rpm, enough for the 500kg T360 to reach a top speed of 62mph. All in all 108,920 examples were built (one every ten minutes), including a number of ‘Snow Crawler’ models with tank tracks at the rear rather than wheels. And if you’d like a fun fact, the AK250E produces more power per litre than the 6.2-litre V8 in the C8 Corvette Stingray. Well, it would if scaled up to a full litre, anyway…
A list of four-cylinder engines would not be complete without one of the most aurally recognisable: the Subaru boxer engine. Subaru did not invent the flat-four boxer, that credit goes to Carl Friederich Benz, founder of Benz & Cie, who made one in 1900. But Subaru’s association with the boxer is stronger than that of any other brand, much in the same way the rotary engine is best associated with Mazda. With that in mind, while there are many fine Subaru boxer engines to choose from, we’ll go back to the very first, the EA-52 in the Subaru 1000. Revealed in October 1965 with sales starting in May 1966, the 1000’s EA-52 engine was a water-cooled, 1.0-litre unit with 55PS (40kW) at 6,000rpm, more than enough for the sub-700kg, front-wheel-drive machine. That engine had a relatively short lifespan, Subaru ceasing production in 1970, but the EA series of boxer engines lived on until 1966, and paved the way for the EJ, FB/FA and FC boxer families. Just imagine seeing an Impreza storming down a rally stage but not hearing that familiar boxer burble? It’s almost unimaginable, and that is the legacy the EA-52 leaves.
If the name ‘Crossflow’ is familiar to you, and for plenty of people who’ve wandered the paddocks of the Revival or watched Goodwood races and highlights online over the years it will be, it’s because it is one of the most popular Ford engines ever. The story begins with the introduction of the Ford Kent engine in 1959 in the Ford Anglia, a 1.0-litre four-cylinder with 39PS (29kW), replacing the Ford Sidevalve engine. Variants followed with more power, more torque, greater capacity and so on, and then in 1967 a redesigned version arrived with a cross-flow cylinder head. This is where the ‘Crossflow’ name originates, and even though the engine was still officially called the Kent, as was the third and final overhaul in 1976, the three iterations became known as pre-Crossflow, Crossflow and Valencia, all because the Crossflow name proved so popular. Not only was the name popular but the engine found its way into pretty much everything, from the Cortina to the Capri, the Escort, Pinto, Sierra and more. It also went into Morgans, Caterhams, Reliants, TVRs and others besides, and has powered a truly ridiculous number of racers to victories all over the globe.
The four-cylinder S14 engine is iconic, and simply couldn’t be missed off from this list. While it might seem odd to have a four-pot M3 now, having been through various six-cylinders and a V8 in subsequent models, the S14 was a perfectly appropriate engine at the time when you consider the E30 M3 weighed only 1,200kg. The S14 was sold in various guises in the M3, from S14B23, 2.3-litre, 200PS (147kW) form in the first E30 M3 through to the S14B23 EVO2 with 220PS (162kW) and the 2.5-litre, 238PS (175kW) S12B23 EVO3. Beyond the road-going M3s, though, the S14 proved to be a racing monster, residing in M3s that won the 24 Hours of Nürburgring five times, the 24 Hours of Spa four times, and powering multiple race and championship winners across the BTCC, DTM and the world of rallying. Few engines can sound quite so angry as the S14.
How could there not be a VTEC motor on here? The EK9 Honda Civic Type R was the very first Civic Type R, following on from the Japanese market NSX Type R in 1992 and Integra Type R in 1995, and USA market Acura Integra Type R in 1997 in what has grown into a long line of ‘Type Racing’ products. The EK9 was sold in Japan only, based on the sixth-generation Civic SiR, but it had a helical limited-slip differential, a close-ratio five-speed manual gearbox, a seam-welded chassis and plenty more besides. The icing on the top was the 1.6-litre B16B engine, a hand ported, naturally aspirated four-cylinder with 182PS (134kW) and 160Nm (118lb ft). The reason it makes our list above the more powerful 2.0-litre in the EP3 that was built and sold in the UK is its character. Not only did it rev seemingly to the stratosphere (9,000rpm), but the cam profiling was incredibly aggressive. The result was a relatively docile motor below 6,100rpm, but then, when VTEC kicked in, the engine went into full lunatic mode.
Sorry, what’s this? Another Honda engine? Yeah, sorry about that – it was unavoidable really, because the F20C is a serious unit. A 2.0-litre, double overhead camshaft VTEC motor, it produced 240PS (177kW), or more in the Japanese market, and revved to 9,000rpm, with 0-62mph taking just 6.2 seconds, peak power at 8,300rpm and VTEC getting going at 5,850rpm. Honda credited its F1 programme for some of the developments, like forged aluminium pistons, lightweight valve springs, an 11:1 compression ratio and a road car world-first use of metal injection moulded rocker arms. At the time of its launch, and for some time afterwards, the F20C meant the S2000 had the most power per litre of any naturally aspirated car on the market, with a whopping 120PS (88kW) per litre, breaking records set by – shock – Honda. We will never see a small, affordable sportscar with an engine quite so bonkers again.
OK, we’ll admit, the EA888 engine is not the most charismatic of four-cylinder engines, but how could we possibly ignore it? Built to replace the EA113, the EA888 has come in 1.8- and 2.0-litre forms, powering cars like the Mk2 Audi TT, the Skoda Yeti, the Mk2 Seat Leon, the Mk6, 7 and 8 Golf GTI, the Audi S3 and more… Versatility is its strong point, which when you’re a company like Volkswagen, with multiple brands and dozens of models to power, is incredibly important. What’s more, the EA888 has proved robust and reliable when it’s come to tuning, too, with tuners able to squeeze out moderate performance gains with very little trouble and no modifications at all, while others have been able to crack more than 500PS (368kW) from the 2.0-litre EA888. Admittedly that is not with a standard turbocharger, and many bits besides, but if an engine doesn’t just detonate with that sort of power running through it then it can only be held in high regard.
How engineers are able to know what’s going on when powertrains are as complicated as this is beyond us. This is the electrified B4204T48, one of the many four-cylinder hybrid engines from Volvo, which you can find in the Volvo S60, V60 and XC60, and the Polestar 1. In the Polestar 1, however, as well as being electrified, it is both supercharged and turbocharged. The 2.0-litre four-cylinder engine uses the supercharger to give the system a boost from idle to 3,500rpm, and from there the turbocharger is in full swing, combining with two electric motors on the rear axle, a crank-integrated starter generator motor and a 34kWh battery (that can push you along for 77 miles on its own, by the way) for a total of 609PS (448kW) and 1,000Nm (740lb ft) of torque. To get an engine to work in a system as intricate as that is a true marvel of mechanical engineering.
We’ve talked about the smallest, the first and one of the most complicated, but what about the most powerful? The most powerful four-cylinder engine title (at the time of writing) goes to the M139 found in the Mercedes-AMG A45S. Previewed in June 2019 and seen a month later at the 2019 Festival of Speed presented by Mastercard, the A45S’s 2.0-litre M139 has 421PS (310kW) and 500Nm (372lb ft) of torque courtesy of twin-scroll, twin-turbos, running through a seven-speed double-clutch to all four wheels. This, then, is a hatchback that’ll hit 62mph in 3.9 seconds and go on to a top speed of 168mph. The engine even has ‘Nanoslide’ piston linings, where a thin, low-friction coating is applied to the inside of the cylinders, a technology that Mercedes says can save several kilos per engine and reduce friction by up to 50 per cent. Each of these engines is also built by just one person. In short, it’s an absolute beast of an engine.
List
Four-cylinder Engines
Mercedes
AMG
A45S
Honda
T350
Subaru
1000
Boxer
BMW
E30
M3
Civic
Type R
S2000
Volkswagen
Polestar